Blood testing for analytes, diseases, infections, and other conditions that may be detected via blood analysis is a useful diagnostic tool. Point-of-care analysis of blood for analytes is very useful and appealing to medical personnel. Such tests, if designed to detect certain analytes, may function better when a premixing set is used. Additionally, when the sample is applied to a cassette containing a test strip, the flow of the sample is important as it affects the accuracy and precision of the test. Therefore, a system with sample flow controls that can receive a sampler is desirable.